Modified polyol-mediated synthesis and consolidation of Gd-doped ceria nanoparticles

A modification of the polyol-mediated synthesis method was developed to synthesize nanostructured gadolinia-doped ceria, Ce_0.9Gd_0.1O_{2 - x}. The oxide prepared by this method had uniform grains with a size of about 2 nm. The work demonstrated the critical role of water in the synthesis. A yield of up to 81% can be achieved. The as-synthesized Ce_0.9Gd_0.1O_{2 - x} nanoparticles are crystalline with a cubic fluorite type structure. The nanopowders were subsequently consolidated by a modified pulse electric current sintering (PECS) method to produce dense samples with an average size below 16 nm and a relative density of about 96%. The dense material is composed of isolated particles instead of agglomerates and provides an ideal sample for investigation of the size effect on the conductivity.